In a frequency division duplexing (FDD) system, a general duplexing solution may be that, resonance filters are respectively implemented on a transmit (TX) channel and a receive (RX) channel using a surface acoustic wave (SAW)/Bulk Acoustic Wave (BAW) process, where these two filters, on one hand, are used as a TX/RX band-pass filter of a radio frequency circuit, and on the other hand, further provide TX-RX separation, and these two filters are coupled together on an antenna port using an impedance matching circuit. However, a primary defect of the foregoing duplexing solution is that, a supported band range is small, and a band is fixed and cannot be tuned, because functions of filtering and duplexing of a TX/RX channel are coupled together and both a working band of a SAW/BAW resonance filter and a working band of the impedance matching circuit are a narrow band, and if multiple modes and multiple bands need to be supported, a plurality of groups of foregoing duplexers is required, which increases cost, an area, and complexity of a radio frequency circuit. In addition, another defect of the solution is that, the solution is incompatible with a time division duplexing (TDD) system where if a TDD system needs to be further supported, a TX/RX channel needs to be connected to an antenna (ANT) using a transmitter-receiver (TR) switch, which also increases cost, an area, and complexity of a radio frequency circuit.